In a new article in the Journal of Politics (gated, I am afraid) a group of Yale scholars (including Donald Green) finds that randomly exposing students to an enhanced civics curriculum increases the students’ knowledge of the constitution and civil liberties but it does not increase their support for civil liberties. This raises the possibility that knowledge and attitudes about civil liberties are causally disconnected. One caveat is that the study does not compare students with “no knowledge” to students with some education. What the evidence shows is that the average marginal effect of going beyond the standard curriculum are zero if we care about support for civil liberties (if we care about knowledge the marginal effect of more education is positive).